Such rotary cutting tools are well known in the art and are used for producing at least one circular groove of a given width, depth and diameter in a work-piece by means of one or more cutting inserts, as the cutting inserts rotate around an axis of rotation of the cutting tool. In these applications it is often required to vary the axial and radial location of at least one cutting insert in order to form grooves of differing widths, diameter or depth and in addition sometimes at least one edge of the groove has to be chamfered. Such cutting tools, with adjustable cutting inserts generally comprise a tool body to which insert bearing cartridges are secured. One of the known methods for obtaining radial adjustment is to use a cartridge with a serrated mounting surface and a tool body with a corresponding serrated body end surface to which the cartridge is secured. In order to alter the axial location of the insert, the cartridge generally comprises two parts, with one part, to which the cutting insert is attached, slidably adjustable with respect to the other part. Such prior art cartridges are known in which the two parts are slidably connected via axially directed serrated surfaces, the two parts being secured to each other by means of a locking screw. In order to perform axial adjustment the locking screw has to be loosened and then tightened after adjustment, as a consequence of which there is a loss of accuracy of the location of the cutting insert's cutting edge as the two parts move away from each other under the influence of gravity. The cutting inserts are secured in insert pockets of the insert bearing cartridges by means of screws. During machining operations, the cutting inserts are subject to cutting forces and centrifugal forces that are absorbed by the screws. This reduces rigidity and stability of the cutting insert, especially at high rotational speeds, causing inaccuracies in the location of the insert's operative cutting edge resulting in poor machining performance. Such forces can also cause bending and even shearing of the securing screw.
U.S. Pat. No. 4,101,239 discloses a boring tool with cutting inserts secured to insert holders (or blade cutters) that are radially adjustable with respect to a body member. The mounting surface of the holders and the end face of the body member are provided with complementary V-shaped grooves which are aligned in the direction of adjustment of the holders. The cutting inserts are not adjustable in the axial direction of the body member. Moreover, each cutting insert is either brazed in an insert pocket, or secured in therein by means of a screw.
U.S. Pat. No. 3,755,868 discloses an adjustable cutting tool of the type in which a cartridge is mounted on a toolholder and may be adjusted either longitudinally or laterally. More specifically, U.S. Pat. No. 3,755,868 describes an adjustable cartridge boring bar of the type frequently used to machine the inner diameter of metal workpieces. A cutting insert is mounted at the extremity of the cartridge by pin-type means. The longitudinal and lateral adjustment is performed by means of two wedges.
Tools employing grooving inserts which are securely retained in tool holders, generally between a base jaw and a clamping jaw, for producing circular grooves in workpieces are disclosed in U.S. Pat. No. 4,332,513 and U.S. Pat. No. 5,638,728. These tools, however, are non-rotating tools that can only machine a given diameter circular groove that is dictated by the shape of the support blade of the base jaw.